The present invention relates to an electric vehicle.
Among vehicles having an electric motor for generating a travel driving force, some vehicles include a structure in which: a swing arm supporting a rear wheel is configured by a power unit including the electric motor; and a rear wheel suspension is disposed between the swing arm and a vehicle body frame above the swing arm as shown by Japanese Patent Application Publication No. Hei 11-79054.
The structure in which the rear wheel suspension is disposed between the swing arm and the vehicle body frame above the swing arm as described above has a problem in that a space above the swing arm cannot be used effectively.
A feature of the disclosed electric vehicle is to provide an effective use of the space above the swing arm.
The electric vehicle disclosed herein includes: a vehicle body frame (for example, a vehicle body frame 11 in the embodiments); an electric motor (for example, an electric motor (or motors) 41 in the embodiments) for generating a travel driving force; a swing arm (for example, a swing arm 34 in the embodiments) swingably provided in the rear of the vehicle body frame, pivotally supporting a rear wheel (for example, a rear wheel 35 in the embodiments) at a rear end of the swing arm; a drive shaft (for example, a drive shaft 52 in the embodiments) for transmitting the driving force of the electric motor to the wheel; and a suspension (for example, a suspension 67 in the embodiments) connecting the vehicle body frame and the swing arm together, wherein: the electric motor is connected to the drive shaft in a way that the electric motor is set in a longitudinal layout in which a rotating shaft (for example, a rotating shaft 42 in the embodiments) is disposed in a front-rear direction of the vehicle, and in a way that the electric motor is disposed, deviated from the center to any one of left and right sides in the vehicle width direction; and the suspension is disposed under the electric motor and the drive shaft, and on the inner sides of the electric motor and the drive shaft in the vehicle width direction, with the position of the suspension in the front-rear direction overlapping the positions of the electric motor and the drive shaft in the front-rear direction.
Additionally, the electric vehicle includes a set of the electric motor and the drive shaft disposed in each of the left and right sides in the vehicle width direction in parallel; and the suspension is disposed between the sets.
Further, the vehicle body frame includes: a head pipe (for example, a head pipe 12 in the embodiments) for pivotally supporting a steering shaft (for example, a steering shaft 14 in the embodiments); a main frame (for example, upper frames 20 in the embodiments) extending rearward from the head pipe; a seat rail (for example, seat rails 23 in the embodiments) extending rearward from the main frame; and a rear sub-frame (for example, rear sub-frames 24 in the embodiments) connecting the main frame and the seat rail together, as well as a storage box (for example, a storage box 95 in the embodiments) is attached to the seat rail by disposing the storage box in a space portion on a lateral side of the seat rail above the swing aim or the drive shaft, or in a space portion between the swing arm or the drive shaft and the seat rail.
Further, as noted the vehicle body frame includes: a head pipe (for example, a head pipe 12 in the embodiments) pivotally supporting a steering shaft (for example, a steering shaft 14 in the embodiments); upper frames (for example, upper frames 20 in the embodiments) extending rearward from the head pipe on an upper side; and lower frames (for example, lower frames 21 in the embodiments) extending rearward from the head pipe on a lower side, and further includes a battery (for example, a battery 80 in the embodiments) for supplying power to the electric motor is detachably disposed in a battery storage unit (for example, a battery storage unit 70 in the embodiments) between the upper frames and the lower frames, and the electric motor is disposed in the rear of the battery storage unit.
The electric vehicle may also include the electric motor which is attached to the vehicle body frame; and the drive shaft is connected to the electric motor by use of a constant-velocity joint (for example, a constant-velocity joint 53 in the embodiments).
The electric vehicle described above may also include the electric motor which swings integrally with the swing arm.
Additionally, the drive shaft transmits the driving force of the electric motor to the rear wheel.
The vehicle body frame, as noted, includes: a head pipe (for example, a head pipe 12 in the embodiments) pivotally supporting a steering shaft (for example, a steering shaft 14 in the embodiments); upper frames (for example, upper frames 20 in the embodiments) extending rearward from the head pipe on an upper side; and lower frames (for example, lower frames 21 in the embodiments) extending rearward from the head pipe on a lower side, and further wherein the position of the lower end of the electric motor is located above the positions of the lower ends of the lower frames, respectively.
The electric vehicle described herein makes it no longer necessary to dispose the suspension in the space above the swing arm, and accordingly makes it possible to use the space above the swing arm effectively, because: the electric motor is connected to the drive shaft in a way that the electric motor is set in the longitudinal layout in which the rotating shaft is disposed in the front-rear direction of the vehicle, and in a way that the electric motor is disposed, deviated from the center to one of the left and right sides in the vehicle width direction; and the suspension is disposed under the electric motor and the drive shaft, and on the inner sides of the electric motor and the drive shaft in the vehicle width direction, with the position of the suspension in the front-rear direction overlapping the positions of the electric motor and the drive shaft in the front-rear direction. Moreover, it is possible to dispose the electric motor, the drive shaft and the suspension compactly in a collective manner in the front-rear direction and the vehicle width direction. In addition, since the electric motor is set in the longitudinal layout in which the rotating shaft is disposed in the front-rear direction of the vehicle, it is no longer necessary to employ a mechanism for converting the direction of the axis of rotation to the front-rear direction of the vehicle, and further reduction in size can be achieved. Additionally, since the suspension is disposed under the electric motor and the drive shaft, the suspension can protect the electric motor and the drive shaft from flying stones and something similar.
Additionally, the electric vehicle described herein makes it possible to achieve equalization of the weight balance by distributing the electric motors and the drive shafts, which are heavy articles, between the left and right sides, as well as by disposing the suspension therebetween, because: the sets of the electric motors and the drive shafts are disposed, respectively, on the left and right sides in the vehicle width direction in parallel; and the suspension is disposed between the sets. Moreover, it makes it possible to reduce the arrangement space in size, and thus to secure a wider space around the arrangement space, because the distribution of the electric motors and the drive shafts between the multiple sets enables reduction in size of the electric motor and the drive shaft which are included in each set.
Additionally, the electric vehicle described above makes it possible to secure a volume for the storage box, because the storage box is attached to the seat rail by disposing the storage box in the space portion on the lateral side of the seat rail above the swing arm or the drive shaft, or in the space portion between the swing arm or the drive shaft and the seat rail.
Further, it is possible to achieve reduction in the size of the vehicle body because the battery storage box is disposed by effectively using the space (straddle portion of the rider) among the upper frames and the lower frames. In addition, it is possible to secure the height for the battery storage box by disposing the electric motor in the rear of the battery storage box.
Still further it is possible to reduce the weight of the swingable article, because: the electric motor is attached to the vehicle body frame; and the drive shaft is connected to the electric motor by use of the constant-velocity joint.
Still further it is possible to build the electric motor and the swing arm in a single unit, and thereby to improve the assembly workability, because the electric motor swings together with the swing arm integrally.
Still further it is possible to use the space in front of the electric motor effectively, because the drive shaft is that configured to transmit the driving force of the electric motor to the rear wheel.
Still further it is possible for the lower frames to prevent the bottom of the electric motor from hitting the road, because the position of the lower end of the electric motor is located above the location of the lower end of each lower frame.